Three component photographic objective of five lens elements



. OCt. 11, G. LANGE THREE COMPON PHOTOGRAPHIC OBJECTIVE 7" 2 2 A 8 OF FLENS ELEMENTS Filed July 14, 1954 x ,1 a 1 3 United States Patent2,720,140 THREE COMPONENT PHOTOGRAPHIC OBJEC- TIVE OF FIVE LENS ELEMENTSGiinther Lange, Konigsbronn, Wurttemberg, Germany,

assignor to Carl Zeiss, Heidenheim (Brenz), Wurttemberg, GermanyApplication July 14, 1954, Serial No. 443,260 Claims priority,application Germany July 24, 1953 Claims. (Cl. 88-57) The inventionconcerns photographic objectives, which consist of five lenses, whichare combined into 3 components in such fashion, that the front componentis an uncemented collective meniscus, which turns its convex side to theobject to be photographed, while the middle component is a dispersivemeniscus, which turns its concave side to the immediately followingdiaphragm, and the rear component shows a collective effect, whereby aswell the dispersive middle component as also the collective rearcomponent each consist of two cemented together lenses of oppositerefractive power, and whereby further the cement surface of the rearcomponent possesses collective action and turns the concave side to thediaphragm.

In accordance with the invention a favorable effect is obtained on thecoma and the astigmatism of the oblique pencils thereby, that oneselects the refractive power (An/r) of the cement surface of the rearcomponent greater than %-l/f, whereby f signifies the focal length I ofthe objective, and thereby, that one at the same time selects the vertexdistance between the concave surface of the middle component adjacent tothe diaphragm and the cement surface of the rear component greater than0.15-f but smaller than 0.50-f and thereby that one besides at the sametime selects the mid-thickness of the total cemented rear componentgreater than 0.40-f-0 but smaller than 1.00-f-0, whereby O signifies themaximal numerical aperture.

Four examples of objectives in accordance with the invention arerepresented in the accompanying illustrations, while in the followingadduced tables the numerical values for these examples are specified.The Figs. 1 to 4 correspond to the Examples I to IV. The method ofreducing the errors of coma and astigmatism of the oblique pencils isillustrated by the following four examples shown diagrammatically inFigures 1, 2, 3 and 4 respectively of the appended drawing.

In the figures and the examples are designated: with r, the radii; withd, the thicknesses; and with l, the distances of the individualcomponents. 7

The values are referred to the focal length f=1. ample I has a relativeaperture of O=1:2 and covers an image angle of :23. The correspondingvalues for the other examples are Example II:6 1:3.5; image angle :15";

Example III: 9:1:4; image angle :14"; Example IV: O=1:4.8; image angle;l4.

Example 11 Thicknesses Lenses Radii and m V (An/r) distances n=+0.513978 +1. 303616 L d|=0. 07326 1. 67003 47. 2

11 =0. 00166 Ta +0. 226305 +2. 741477 Lu da=0. 10689 1. 62041 60.3

n 5. 93534 0. 017355 Lm ds=0. 01498 1. 72342 38. 0

1; =0. 17648 n =+7. 26026 +0. 096627 Lrv d4=0. 14818 1. 70154 41. 1

r1 0. 172163 +0. 569925 Lv ds=0. 06327 1.60342 38.0

Example III Thicknesses Lenses Radii and M V (An/r) distances n=+0.494833 +1. 347364 Ll d1 =0. 07259 1. 66672 48. 4

11 0. 00165 T; =+0. 227492 +2. 727173 L d2=0. 10558 1. 62041 60. 3

n 2. 86392 0. 035968 Lm. d;=0. 01485 1. 72342 38.0

l2=0. 20456 To +3. 50314 +0. 200260 L v.-." d4=0. 07259 1.70154 41.1

0. 171825 +0. 582802 L di=0. 06929 1.60140 38.3

Example I V Thlcknesses Lenses Radii and 114 V (An/r) distances n=+0.488067 +1. 372824 L; d1=0.072611' 1. 67003 47. 2

l1=0.001667 n=+0. 227628 +2. 725543 Ln d2=0.105278 1. 62041 60. 3

r4 2. 211734 0. 046574 Lnr. lia=0.013889 1. 72342 38. 0

h 0.205556 Te== +2. 784391 +0. 251955 L1V----- dl=0.061111 1. 70154 41.1

0. 171928 +0. 582453 Lv ds=0.073889 1. 60140 38. 3

I claim:

1. Photographic objective consisting of five lenses, which are combinedinto three components in such fashion, that the front component is anuncemented collective meniscus, which turns its convex side to theobject to be photographed, and that the middle component is a dispersivemeniscus, which turns its concave side to the immediately followingdiaphragm, while the rear component is of co ec me e ec ereby as wellthe dispersive middle component as also the collective rear componenteach consist of two cemented together lenses of opposite refractivepower, and whereby further the cement surface of the rear componentpossesses collec: tive action and turns the concave side to thediaphragm, thereby characterized, that the refractive power (An/r) atthe cement surface of the rear element is greater than l/f, whereby fsignifies the focal length of the objective, and that the vertexdistance between the concave surface of the middle component adjacent tothe diaphragm and the cement surface of the rear component is greaterthan 0.15-f but smaller than 0.50-f, and that the midthicknesspf thecemented rear component is greater than 0.40-f'6, but smaller thanLOO-f-C I, whereby O signifies the maximal numerical aperture, r theradius of curvature of the cement surface in the rear component, An thedifference in refractive index of the cemented lenses of the rearcomponent, and f the equivalent focal length of the objective.

2. Photographic objective according to claim 1, thereby characterized,that the refractive powers (An/r) each deviate at most by :0.2/f and thelens thicknesses (d) and the air distances (1) each by at most :0.1-ffrom the value to be taken from the following numerical example:

where L: to Lv refer to the lens elements starting with the front side,r1 to re are the radii of curvature of the refractive surfaces fromfront to rear as indicated in the drawing, the and signs referrespectively to surfaces convex and concave to the front, d1 to d5 arethe axial thicknesses of the elements, 11 and I2 are the axialseparations of the lens elements, nu is the index of refraction withreference to the d-line of the spectrum, V is the dispersive index, An/ris the respective refractive power for each refractive surface n beingthe difference in refractive index between two adjacent lens elements.

Thlcknesses Lenses Radll an m V (An/r) distances n=+0.5a1o42-r+1.290197-1/r L; d1=0.09%4-1 1. 69289 52. 4

li=0.00l91-1 n=+0.297675-1 +2.092853-1/1 Ln dz=0.13853-1 1. 62299 58. 1

n= -1.90549-1 0.052706-1/1 I/m d1=0.01601-1 1. 72342 38. 0

l: =0.l1052-1 Ts=+7.05926-1 +0.101569-1/1 Lrv d|=0.28963-1 1. 71700 47.9

0.196112-1 +0.475542-1/1 Lv tis=0.17340-1 1. 62374 45. 0

where L1 to Lv refer to the lens elements starting with the front side,r1 to re are the radii of curvature of the refractive surfaces fromfront to rear as indicated in the drawing, the and signs referrespectively to surfaces convex and concave to the front, d1 to d5 arethe axial thicknesses of the elements, It and I: are the 4. Photographicobjective according to claim 1, thereby characterized, that therefractive powers (An/r) each deviate at most by :0.2/f and the lensthicknesses (d) and the air distances (I) each by at most 1:0.l-f fromthe values to be taken from the following numerical example:

Thlcknesses Lenses Radil an m V (An/r) distances n=+0. 49418334 +1.347364-1/1 L d1=0. 07259-1 1. 66672 48. 4

ds=0. 01485-1 1. 72342 38. 0 n=+0. 161049-1 4. 4191925 1/1 lz=0. 20456-1ra=+3. 50314 1 +0. 200260-1l1 Lrv d4=0. 07259 '1 1. 70154 41. 1

r1==0. 171825-1 +0. 582802-1/1 Lv ds=0. 06929-1 1. 60140 38. 3

axial separations of the lens elements, m1 is the index of refractionwith reference to the d-line of the spectrum, V is the dispersive index,An/r is the respective refractive power for each refractive surface nbeing the difference in refractive index between two adjacent lenselements.

3. Photographic objective according to claim 1, thereby characterized,that the refractive powers (An/r) each deviate at most by 1-0.2/f andthe lens thicknesses (d) and the air distances (I) each by at most iOJ-ffrom the values to be taken from the following numerical 60 where Lr toLv refer to the lens elements starting with the front side, r1 to rs arethe radii of curvature of the refractive surfaces from front to rear asindicated in the drawing, the and signs refer respectively to surfacesconvex and concave to the front, d1 to da are the axial thicknesses ofthe elements, It and I: are the axial separations of the lens elements,na is the index of refraction with reference to the d-line of thespectrum, V is the dispersivev index, An/r is the respective refractivepower for each refractive surface n being the difference in refractiveindex between two adjacent lens ele- 5 6 5. Photographic objectiveaccording to claim 1, thereby of refraction with reference to the d-lineof the spectrum, chafacteriled, that the fefractlve Powers each V is thedispersive index, An/r is the respective refracdevlate at most by andthe lens thlcknesses (d) tive power for each refractive surface n beingthe differand the air distances (1) each by at most. p ence inrefractive index between two adjacent lens elethe values to be takenfrom the following numerical 5 example: mems' Thtcknesses f Lenses Radliand m V (An/r) distances r1=+0. 4880674 +1. 372824- 1 LI d1 =0. 072611-1 1. 67003 47. 2

r4=+1.478l68-f 0.4ss2s4-1/t z1=0. 0016614 r==+0. 2276284 +2. 725543-1 1Lu d,=0. 1052184 1. 62041 60.3

-2. 2117341 -0. 046574- 1/: Lm d1=0. 0138894 1. 72342 38.0

r5=+0.161150-t -4. 4s9110-1/r Z1=0.205556-t n=+2. 784391-! +0. 251955.1/: LIV d4=0. 0611114 1. 70154 4111 r1= 0.11192a-r +0. 5s2453- 1/: Lvd1=0. 073889-f 1. 60140 as. 3

where L1 to Lv refer to the lens elements starting with References Citedinthe file of this patent the front side, r1 to ra are the radii ofcurvature of the 25 UNITED STATES PATENTS refractive surfaces from frontto rear as indicated in 1880 394 Altman Oct 4 1932 the drawing, the andsigns refer respectively to 1:975:678 Bertele Oct. 1934 surfaces convexand concave to the front, d1 to d5 are 2 133 523 Bertele Jam 30 40 theaxial thicknesses of the elements, 11 and l: are the 2 5 2,012 Bertele J1y24 1951 axial separations of the lens elements, m1 is the index 302,623,434 Bechtold Dec. 30, 1952

